Brake-shoe art



June 29 1926. 1,590,847

L. F. MCORE BRAKE SHOE ART Filed Jan. 2, 1926 x; 27 3 ,W INVENTOR.

/ BY MAJ ATTORNEY Patented June 29, 1926.

UNITED STATES PATENT OFFICE.

LEWIS F. MOORE, OF ROANOKE VIRGINIA, ASSIGNOR TO WALKER MACHINE & FOUNDRY CORPORATION, OF ROANOKE, VIRGINIA, A CORPORATION OF VIRGINIA.

BRAK -snot: An'r.

Application filed January This invention relates to brake shoes to be ,ap lied to brake equipment to engage the whee s ofrailway cars and railway locomotives.

The invention is especially applicable to cast metal brake shoes, the body of the shoe having embedded. in it strips or sheets of reinforcing metal, such as wires placed side by side or interwoven or sheet metal perforated or reticulated.

The object of this invention is to provide a cast meta-lbrakev shoe in which parts are chilled and in which shoe the reinforcing members are effectively brought into engagement or .union' with the cast metal in all parts of the shoe: K

By way of introduction, the construction of my improved brake-shoe, when completed, maydbe stated as follows. The ends ate the mo in which the brake shoe is to be cast.

I serve to chill and harden the ends of the brake shoe. This chilling involves a-relatively ra id cooling of the adjacent molten metal, w ereby the time during which the reinforcing member or members are exposed to the high heat of the molten metal 1s made relatively short. Furthermore, the manner of pouring the molten metal delivers the metal into the ends of the mold at less heat than in the intermediate part of the mold. The molten metal is'poured. into the intermediate part and made to flow thence into the ends. During such flowing a part of the heat is lost. The other parts of the mold have sand faces which permit .slow or prolonged coolin of the a jaoent molten metal, whereby t e reinforcing material 1s exposed to the intense heat of the molten metal during a relatively long time. Here tofore it has been found that in the casting of brake shoes containi such reinforcing members and the mo ld not containing chilled blocks, that the reinforcing member or members are burned or partially destroyed throu' h the action of the prolonged high heat in t e molten metal deliveredinto the mold. To prevent such burning or artial destroying, the reinforcing 'mem ers have been coated with a material adapted to resist heat or prevent oxidation of the reinforcing members in the presence ofthe high heat. It being desirable, for the purpose of making a brake shoe strong and hard and.

therefore durable in, service, I have chilled 2, 1926. Serial 116,715,945,

prolonged heat present in the 'mold after the pouring of the molten metal. For such coatlng, the prior art shows the use of various materials. I have used ound soap stone and mineral oil combined fifore using. Then I found that oxidizing of the reinforcing members in the part'of the shoe not affected by the chilling was substantially absent; but I also found that such coating prevents the complete engagement or union of the molten metal with the parts of the reinforcing -members= embedded chilled parts of thestru'cture, the coating serving as a separating -medium. To allow or cause the reinforcing members'to actually reinforce, such complete engagement or in the 1 umon is. essential, and to make the brake shoe efficient, it is especially important that the end strength H y reinforcing. Noting this action of the coating on the parts'of the reinforcing members embedded in the chilled end parts of the shoe, I found by experimenting and testing that the imperfect enga ement or union between the cast metal an the reinarts of the shoe be given ample the parts ,85 forcing members in those parts ofvthe shoe. can be avoided by coating 0111 of the reinforcing'members gwhic do not extend into the parts or regions of the structure which are afiectedbythe chilling. On

the contrary, by such experimenting and testing it was disclosed that by thus coatin the parts of the reinforcing-members vwhic were to lie in the region of prolonged heat and not coating the parts of the reinforcin members which were to lie in the regionso short duration of heat, in the finished structure the parts of the reinforcing members which lie in the. region of prolonged heat Fig. 2 is a cross section on the line, 22, of Fig. 1;

Fig. 3 is an upright section through one end of a mold used for molding these brake shoes;

Fig. 4 is an upright section on the line, 4-4, of Fig. 3.

Referring to the drawings, A, is a plate metal back. 13 is the cast metal part of the shoe. C, C are reinforcing members embedded in the cast nretal and',extend'ing "throughout the length of the structure.

Structures like that described in connection with Figs. 1 and 2 have heretofore included the reinforcing members coated with material intended to prevent oxidizing or 1 chilled blocks make-each end of the hot casting a quick cooling part or region extending approximately as far as the line, aa, in Figs. 1' and 3. g

In preparing the reinforcing members for placing them into the mold, the parts between the lines, a-a, are covered or coated with material serving to prevent burning or oxidation of those members, and the parts of said members extending from each line, (i a, to the ends of those members are left without such coating.

When, as above indicated, the reinforcing members thus prepared are placed into the molds and the molten metal is poured into the mold, prolonged cooling of the molten metal and prolonged exposure of the parts of the reinforcing membersbetween the lines, aa, take place, while in the ends of the molds relatively quick cooling takes place during such a short time as to avoid exposing the adjacent parts of the reinforcing members to such heat as will cause burning or oxidizing of those parts of those members, those members being thus left in condition for complete engagement or union with the cast metal.

It, is inferred that when the coating is present on the reinforcing metal and that vmetal and the coating are exposed to the prolonged heat of themolten metal poured into the mold, the coating is-entirely or partially converted and absorbed or neutralized in such manner as to cease to constitute a layer or medium separating the oured metal from the reinforcing metal, an that in the chilling re ion the heat is not sutliciently intense or pro longed to thus convert and absorb or otherwise eliminate the coating and prevent a forcing it from remaining as a medium separating the reinforcing metal from the poured metal.

In a secondary way, complete engagement between the reinforcing members and the chilled ends of the shoes is also important, because even if in service, the end of a shoe fractures, the reinforcing members will prevent the falling of the fractured part to the rail and perhaps cause wrecking. It is well known in railway service that every effort should be made to prevent any part of a brake mechanism from falling so as to be in the way of a wheel. Wrecks of parts of a train and in some cases an entire train have been thus caused.

I claim as my invention,

1. A cast metal brake shoe comprising a chilled part and an unchilled part, and reinforcing material embedded in the chilled part and in the unchilled part of the body, the part of the reinforcin material in the unchilled part of the body eing coated with heat resisting material and the part of the reinforcin material in the chilled part of the 'body eing bare, substantially as described.

2. A cast metal brake shoe comprising chilled ends and an intermediate unchilled part, and reinforcing material embedded in the chilled ends and insaid intermediate part and the part of the reinforcing material in said intermediate part being coated with heat resisting material and the part of the reinforcing material in the chilled ends being bare, substantially as described.

3. A brake shoe having a cast metal body in which the ends are composed of chilled metal and the art between the ends is composed of unchllled' metal, and metal reinforcin embedded in each chilled end and extending into the unchilled metal of the bod the part of the reinforcing in the unchil ed part of the body'bein covered with heat resisting material and t e art of the reinforcin 1n the chilled ends eing bare, substantia ly as described.

4. A brake shoe having a cast metal body in which the ends are composed of chilled metal and the part between the ends is composed of unchilled metal, and metal reinembedded in each chilled end and extending through the unchilled metal of the bod the part of the reinforcing in the un" chil ed part of the body bein covered with heat resisting material and t e art of the reinforcin in the chilled ends heing bare, substantially as described.

5. The herein described method of forming a cast metal brake shoe, which method consists in coating a part of a reinforcin material with heat resisting material and leaving a part of said reinforcing material bare, and then pouring molten metal around the reinforcing material and chilling the molten metal. at the part of the reinforcing material which is bare and slowly cooling the part of the molten metal surrounding the part of the reinforcing material which is covered with the heat resisting material, substantially as described.

6. The herein described method of forming a cast metal brake shoe, which method consists in coating the middle part of a reinforcing material adapted to extend into the ends and intermediate part of the body of the shoe with heat resisting material and leaving'the end parts of the reinforcing material bare, and then pouring molten metal around the reinforcing material and chilling the molten metal at the ends ofthe molded body and slowly cooling the part of the body intermediate the end $31133 of the body, substantially as describe 7. The herein described method of making reinforced cast metal brake shoes havmg chilled ends, which method consists in placing a coating of heat resisting material on the part of the reinforcing material which is to be embedded in the unchilled part of the shoe and leaving the remainder of the reinforcing material bare, and then pouring molten metal around the reinforcname, this 31st day of December, in the year one thousand nine hundred and twentyfive.

' LEWIS F. MOORE. 

